From 6dd2dfb6788786fb4adc4f1f0a09f59c5f25cce0 Mon Sep 17 00:00:00 2001
From: David Brochart <david.brochart@gmail.com>
Date: Wed, 26 Feb 2025 09:06:38 +0100
Subject: [PATCH] Ensure IPython's HistoryManager threads don't leak

---
 tests/conftest.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tests/conftest.py b/tests/conftest.py
index 76e780af3..79d0edc27 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -11,6 +11,7 @@
 import zmq.asyncio
 from anyio import create_memory_object_stream, create_task_group
 from anyio.streams.memory import MemoryObjectReceiveStream, MemoryObjectSendStream
+from IPython.core.history import HistoryManager
 from jupyter_client.session import Session
 
 from ipykernel.ipkernel import IPythonKernel
@@ -29,6 +30,10 @@
     tracemalloc = None
 
 
+# ensure we don't leak history managers
+HistoryManager._max_inst = 1
+
+
 @pytest.fixture()
 def anyio_backend():
     return "asyncio"